turnigy nano teck 2500mah 3s1p5-10c transmitter lipo pack ID # 9210000037

Just recieve this battery. There are 3 leads what is the smaller plug for. Is that the charging cable? Is there a plug number for it? Like the balance plug number is JST-XH. i want to but this battery in my 6ex Futaba TX. Can you please help me!!! thank you Ernie